0000000000653305

AUTHOR

Sunghun Lee

0000-0002-1974-8110

Studying the reduction of graphene oxide with magnetic measurements

Abstract The reduction of graphene oxide is one of the most facile methods to fabricate a large amount of graphene. The reduction rate is generally examined by various spectroscopic techniques, but each technique is applied for different purposes. Herein, we demonstrate the correlation between spectroscopic results and magnetic data, which plays an important role in determining the quality of reduced graphene oxides. The magnetic signals are related with the carbon-oxygen functional groups analyzed by spectroscopic tools. Especially, highly reduced sample exhibits the diamagnetic property similar to graphene-like materials. This report can provide an insight to determine the reduction rate …

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New Approach to Determine the Quality of Graphene

The reduction of graphene oxide is one of the most facile methods to fabricate a large amount of graphene and the reduction rate of graphene oxide is related with the quality of synthesized graphene for its possible application. The reduction rate is usually determined by using various spectroscopy measurements such as Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Here we propose that the magnetic data can be used as a means of determining the quality of graphene oxide (GO) and reduced graphene oxide (RGO) by the investigation of close relation between magnetic moment and chemical bonding state. Our experimental findings and previous theo…

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Highly Reduced Saturation Magnetization in Epitaxially Grown Ferrimagnetic Heusler Thin Films

The key of spintronic devices using the spin-transfer torque phenomenon is the effective reduction of switching current density by lowering the damping constant and the saturation magnetization while retaining strong perpendicular magnetic anisotropy. To reduce the saturation magnetization, particular conditions such as specific substitutions or buffer layers are required. Herein, we demonstrate highly reduced saturation magnetization in tetragonal D022 Mn3–xGa thin films prepared by rf magnetron sputtering, where the epitaxial growth is examined on various substrates without any buffer layer. As the lattice mismatch between the sample and the substrate decreases from LaAlO3 and (LaAlO3)0.3…

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